Data Modelling For Software Engineers (Devoxx GR 2025).pdf
- 1. DATA MODELING FOR SOFTWARE ENGINEERS G E T T I N G Y O U R E N G I N E E R I N G L E A D E R S T O S M I L E A G A I N G E T T I N G Y O U R D A T A L E A D E R S T O S M I L E A G A I N G E T T I N G Y O U R A R C H I T E C T S T O S M I L E A G A I N G E T T I N G Y O U R P R O D U C T L E A D E R S T O S M I L E A G A I N G E T T I N G Y O U R O R G A N I Z A T I O N T O S M I L E A G A I N © 2025 Scott C Sosna scott-sosna
- 2. Data Architect Product Software Engineer Leadership Standards Legal Database Admin Data Modelers
- 3. 3 ANY CONCERNS? Problem Statement Data Capture End-to-end Usability Duplicate Work
- 4. No time to de fi ne end-to-end data vision, get out of my way and let me start coding! S O F T W A R E E N G I N E E R X “
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- 6. 6 DATA IS FOREVER …but your software is not… "Wiktionary Word ER Data Model" by NoX is licensed under CC BY-SA 3.0. "Linking-Human-Diseases-to-Animal-Models-Using-Ontology-Based-Phenotype-Annotation-pbio.1000247.g003" by Washington N, Haendel M, Mungall C, Ashburner M, Wester eld M, Lewis S is marked with CC0 1.0. "Salesforce Product and Price Book Data Model" by Softbuilder is licensed under CC BY-SA 4.0. "ER Diagram MMORPG" by TheMattrix at English Wikipedia is licensed under CC BY-SA 3.0.
- 7. 7 Architect Enterprise, Solution, Application, Integration, Data Who Am I? Life-long technologist (nerd) searching for interesting problems to solve in innovative and sustainable ways. Engineer Full-circle return to full-time software engineer. Speaker/Writer/Mentor Enjoy sharing expertise, knowledge, experiences, insights, and everything else. Traveller Too many interesting places and so little time!
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- 9. 9 TODAY’S GOALS Becoming Data First Driven top-down not bottom-up, requires senior leaders’ buy-in, replaces existing processes, changes culture. De fi ning Career Path Impacted by business goals, role diversity, personal goals, no simple answer for any one person. Data Modeling Tutorial Industry, technology, non-functional requirements, culture impact organizational approach. Data Modeling 101 Design/implementation decisions impact your solution’s overall viability … and your organization’s success. Decouple, Please! How outsiders consume your data may not match its internal representation …. and that’s not necessarily bad. Wrap Up Final thoughts, other things to consider, etc.
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- 11. 11 Definitions How is data used in your solutions?
- 12. 12 CATEGORIZING DATA Some obvious, some not Messaging APIs Persisted Hardware Generated
- 13. 13 HOW IS DATA USED? Application Data maintained and shared in your solution supports day-to-day business activity. Reporting Aggregated data provides view of state of business and identifies new opportunities. Integration You and outside providers exchange data for mutually beneficial reasons. Intellectual Property Your data differentiates you from competitors and is your company’s raison d’état.
- 14. Data is like garbage, you’d better know what you are going to do with it before you collect it. M A R K T W A I N ( M A Y B E ? ) “
- 15. 15 Data Modeling 101 Data Modeling screams waterfall: data models always preceded code. Not today. Today, code changes to implemented data structures in whatever form is modeling data: persisted, published, exchanged, cached, measured.
- 16. 16 Formal Data Models Few created, fewer reviewed, none accurate. Need To Know Key points to realize before you start…. What Code Comments? No IDE to open, no inline comments to review. All Changes Impactful No inconsequential changes, everything visible to world.
- 17. 17 CONSISTENCY Naming Data naming more important than code naming: name visible to everyone. Data Type Choose a data type and stick with it. Epoch or structured date/time for timestamps? String, number, native for booleans? Decimal points on a percent? Enums to represent closed set of values? Structure Consistency reduces cognitive complexity, increases productivity, reduces bugs. Validation Validate once, validate always: database constraints, data type limitations, common code libraries.
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- 19. The good thing about standards is that there are so many to choose from. A N D R E W T A N E N B A U M “
- 20. 20 International Standards Rarely need to create your own, so don’t! Industry Corporate Business De facto
- 21. 21 OTHER CONSIDERATIONS Never Means Maybe Certainty is fleeting: when business needs change means implementation change. Stakeholders Often Guess Stakeholders often start with partial or incorrect understanding, leading to multiple iterations and changing data requirements. Challenge their pronouncements. Accept Problem Statement, Not Solution Don’t accept proposed solutions which ignore current reality. You own/understand the domain, their solution becomes your future problem. Anticipate Future But Implement Selectively Listen to functionality discussions carefully to anticipate and (perhaps) future-proof your data design.
- 22. 22 Don’t … Ignore Compliance and Security Abuse Optionality or Flags Use Business Keys Don’t Codify ALL and NONE Store Localized Data Don’t Repeat Yourself
- 23. When in doubt, talk it out. S C O T T S O S N A “
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- 25. 25 Decouple, Please! Consumers whom know - or think they know - your data often implement in ways that make it difficult to evolve your data later. Keep Data Behind Closed Doors
- 26. The ability to evolve your data implementation is inversely proportional to outsiders’ knowledge of current state. S C O T T S O S N A “
- 27. 27 KEEP YOUR SECRETS Again, some obvious, some not. Structure Identity Validation Flow
- 28. 28 INTERNAL EXTERNAL BALANCING ACT Are you lenient with consumers within your organization?
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- 30. 30 Wrap Up Anything else?
- 31. 31 Image Credits Software Engineer: Expression icons created by Freepik (FreePik) Documentation: Standards icons created by surang (FreePik) Legal: Barrister icons created by Vectors Tank (FreePik) No Sign Paint Brush Style by Free Vector (FreePik) Data Architect: Businesswoman icons created by pojok d (FreePik) Product owner: Business person icons created by Freak (FreePik) CIO: Professions and jobs icons created by juicy_ fi sh (FreePik) Primary icons created by Mohamed Mbarki (Flatiron) decision tree icons">Decision tree icons created by Freepik (Flaticon) “A Diamond is Forever” De Beers Group Website adiamondisforever.com Vsevolod Mikhailovich Garshin (1855–1888) by Illia Repin, The Metropolitan (https://www.metmuseum.org/art/collection/search/437442) Database icons created by phatplus (Flaticon) Api icons created by Laura Reen (Flaticon) Email icons created by ChilliColor (Flaticon) Data Engineer: Nerd icons created by icon fi eld (FreePik) Smart watch icons created by Freepik (Flaticon) "Andrew tanenbaum froscon" by Smalltown Boy at German Wikipedia is licensed under CC BY-SA 3.0. "Decision Making" by SimonDoggett is licensed under CC BY 2.0. "The past fades away, while the future stays out of sight." by Luke Hay fi eld Photography is licensed under CC BY 2.0. https://xkcd.com/927/ Rules icons created by Vectors Tank (Flaticon) 3d-render-abstract-background-with-cyber-particles-design by kjpargeter (Freepik)